Building moisture meter Hydromette BL Compact B. It features a minimum and hold function, displaying moisture in percentage by weight or CM percentage. The device includes characteristic curves for seven building materials and an acoustic alarm function that activates when a user-defined limit value is exceeded. It offers automatic calibration upon switching on and automatic device switch-off. The meter allows for non-destructive measurements using a ball probe and is suitable for recording moisture in building materials, also serving as a pre-tester for CM measurements.